Wish I knew the answer. I don't fuck with carbs. The last few engines we built that had carbs we called our tuner in to dial it in. The newer cars we have him do pcm calibrations in the dyno.
If it's actually flooding its probably a float, needle, or seat problem. Most likely the float still isn't set correctly.
You could pull the top of the carb off. Attached a couple foot length of hose to the fuel connection and hold it up in the air. Set the top of the carb on something else so it's resting on the floats (needle valves closed) Fill the hose with water or gas and see if you get leakage. If you do keep adjusting and repeating until it stops.
Float's gotta be stuck. Get a rebuild kit and do it again.
Ethanol destroys those little things in no time.
Edit...AND check the little rubber plugs on the back of the carb for the lines not being used. I had one that cracked and was sucking air. It'll make it run instantly bad like yours did. It's a 10 cent fix and very common.
Fuck you, that oval has put food on my family's table since 1925.
If you want to discuss the welding on that truck come see me. If you want to discuss the engine call somebody else, cause I don't know shit beyond...put gas in and go.